PREVENTER FOR WELLS WITH TWO-ROW STRING Russian patent published in 2020 - IPC E21B33/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to sealing equipment of wellheads of oil and gas wells during their operation and repair in order to ensure safety, prevention and elimination of oil, gas and water ingress, including on ultraviscous oil (UVO) wells with inclined mouth of double-row pipe string, protection of entrails and environment, which provides simultaneous performance of lowering and lifting operations of two columns: a pipe string with couplings and a flexible pipe string, without their interaction with each other at the wellhead inclined well. Preventer for wells with two-row pipe string comprises upper and lower flanges rigidly connected to housing equipped with vertical circular axial channel. Relatively to the axial channel there are symmetrically arranged two lateral horizontal channels, longitudinal axes of the side horizontal channels are located perpendicular to the axis of the vertical channel. In the first horizontal channels made in the housing with the possibility of longitudinal movement there installed are ram blocks, in which there are tube rams equipped with elastic seals, and manual control drives of rams, which include driving rods of rams, having threaded connections for interaction with lids screwed into housing, at that cavities of bodies of ram blocks in cross section have rectangular shape, and elastic seals are arranged in slots made in tube rams. In the second horizontal channels located in the upper flange, in the sealed version from the outside, there are screwed side screw supports, interacting with the sliding sliders, which are equipped with key slots, and upper flange is equipped with keys, installed in key slots of sliding slides, having the possibility of longitudinal movement within key slots, connecting and sealing dimensions of lower flange of preventer are made corresponding to that of support flange of wellhead equipment, on which preventer is attached, wherein elastic seals are made of heat-resistant rubber. Ram blocks with tube rams in the first horizontal channels are equipped with two semi-ring recesses with slots. In the second horizontal channels there are sliding slides with additional tube rams equipped with two semi-ring recesses. In slots of semi-ring samples of each of tube and additional pipe rams sealing elements are installed and fixed, which are made in the form of heat-resistant elastic seals, and also centering elements made in the form of semi-rings. Central axes of the semi-ring recesses of the tube rams and central axes of the semi-ring samples of the additional tube rams are located eccentrically on the opposite sides of the central axis of the axial channel of the casing at angle of 180° between each other and at a distance providing centering of pipe strings relative to axial channel of preventer body in inclined well and alternate or simultaneous sealing of pipe string with couplings and string of flexible pipes in case of oil and gas occurrence, at that, the ram blocks are arranged in horizontal channels with the possibility of simultaneous performance of lowering and lifting operations of two columns: a pipe string with couplings and a flexible pipe string, without their interaction with each other at the wellhead inclined well.

EFFECT: preventer for wells with two-row pipe string allows to expand preventer technological capabilities, as well as to improve sealing quality of two pipe strings at the well UVO inclined well head, as well as higher safety of operations in case of OGWI occurrence at wellhead of inclined well UVO and reduced duration of lowering-lifting operations.

1 cl, 4 dwg